Multiple glazed unit



March 17, 1959 w. s. BOBEL MULTIPLE GLAZED UNIT Filed 'Jan. 17, 1958 FIG. 2

FIG.1

a R 1 m5 NM United States Patent MULTIPLE GLAZED UNIT William S. Bobel, New Kensington, Pa., assignor to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania Application January 17, 1958, Serial No. 709,655 3 Claims. (Cl. 20-565) This invention relates to a multiple glazed window construction and it has particular relation to such construction having an improved means for mounting a light modifying screen in the air space between the sheets of glass forming the unit.

Multiple glazed units comprise two or more sheets of glass spaced from one another to provide an insulating air space between the sheets. This air space is effective for reducing the passage of heat through the unit due to conduction and convection, but does not satisfactorily reduce heat transmission through the unit due to radiation. It is known to support a light modifying screen in the air space between the sheets. Such screens are in the form of fixed or adjustable Venetian blinds and serve to reduce passage of sunlight through the unit, reduce glare or light passing through the unit and reduce transmission of radiant energy through the unit due to radiation.

' Conventional light modifying screens contemplated for use in the present invention are composed of horizontal louvers or slats strung together one above the other and spaced from each other by suitable wire stringers which pass through or around each slat. The slats are tilted at a slight angle to the horizontal so as to reflect a portion of the suns rays.

Problems have been encountered in mounting these light modifying screens within a multiple glazed unit'so v as to obtain uniform transmission of light. The screen should be maintained in one straight plane. If there are any undulations or wavy portions in the screen, the angle of the slats to the horizontal in these portions will differ from the angle of the slats in other portions in the screen. In such case, the pattern of light transmitted through the screen is non-uniform and the reflectance of the suns rays is non-uniform.

One method employed to maintain the screen in a single plane between the sheets is to have the sheets of glass in touching relationship with the screen on both sides of the screen. This method is unsatisfactory, for the thickness of the screen is small and the resulting air space between the sheets is not suflicient to prevent substantial heat transfer by conduction and convection and to provide substantial thermal insulation. The thickness of the screens contemplated for use in the present invention is of the order of A inch, whereas, it is desired that the air space be approximately 4 to as inch in thickness.

An object of the present invention is to provide a multiple glazed unit having a light modifying screen mounted therein in an air space of greater thickness than the thickness of the screen.

A further object of the invention is the provision of a means to mount the screen in a straight plane which is parallel to the glass sheets and which is designed to prevent undulations in the screen and variations in light transmission and heat transmission through the screen and the multiple glazed unit.

' Another object of the invention is'the provision of a 2,877,516 Patented Mar. 17, 1959 means for mountingvthe light modifying screen within the unit in a manner so that it does not place undue stresses on and cause displacement of the elements which are employed to separate the glass sheets at their marginal edges.

Other objects and advantages .of the present invention will become apparent by reference to thefollowing description of the drawing in which like numerals refer to like parts throughout:

In the drawing: Fig. 1 is an elevation of a multiple glazed unit embodying the present invention;

Fig. 2 is a partial isometric'view of the multiple glazed unit of Fig. 1 illustrating the relationship of the various elements of the unit to each other; Fig. 3 is a view in section taken along lines IHIII of Fig. 1;

Fig. 4 is an elevation of a multiple glazed unit illustrating another embodiment of the present invention; 7

Fig. 5 is a partial isometric view of the multiple glazed unit shown in Fig. 4 illustrating the various elements'in the unit and their relationship to each other; v

Fig. 6 is a view in section taken along lines VI-VI of Fig. 4; and

Fig. 7 is a partial isometric screen which is useful in the the present invention.

A multiple glazed unit 10 containing a light modifying screen 12 mounted therein is shown in Figs. 1, 2 and 3. The unit is composed of two sheets of glass 13 and 14 separated at their marginal edges by spacer elements 16 and 17 so as to form an air space 19 between the glass sheets. The outer or peripheral edges of the glass sheets 13 and 14 and the spacer elements 16 and 17 are substantially flush with each other. It is preferred that the spacer elements be flush with the edges of the glass sheets; however, they may be recessed slightly, for example, about 3 32 inch in from these edges. The sheets of glass may be tempered, colored, laminated or have other special strength or optical properties, such as the ability to absorb ultraviolet and/or infrared rays.

The spacer elements 16 and 17 are in the form of hollow metal tubes of rectangular cross-section running completely around the edges of the unit between the view of a light modifying multiple glazed unit" of marginal edges of the glass sheets. These tubes can be made of rolled, extruded or drawn metal sections, for example, of extruded aluminum or drawn steel. It is understood that the spacer elements may be of different cross-section or may be solid as desired. It is the usual practice for the spacer elements to have a desiccant22 in the inside thereof. The spacer elements 16 and 17 are provided with spaced openings 24 connecting the interior 19 of the unitwith the desiccant 22 so that the moisture from the air within the unit may be absorbed.

The spacer elements 16 and 17 are adhered to the marginal edges'of the glass sheets 13 and 14 and to each other at their meeting faces by means of a thin, continuous film ofa moisture and vapor impervious, mastic composition 28. A composition which has been found to be satisfactory is a dispersion of carbon black in polyisobutylene such as set forth in U. S. Patent No. 2,551,952, granted to Gerald E. Kunkle. Other moisture and vapor impervious, adhesive, caulking compositions may be employed but the above composition is preferred.

In accordance with the present invention, the light modifying screen 12 is mounted within the air space 19 by being suspended and held tightly between the marginal edge spacer elements 16 and 17 and embedded in the mastic 28 locatedbetween the spacer elements. 16 and 17. As shown in greatly enlarged form in ,Fig.-7 the screen 12 may comprise a series of small, thin, para1- lel strips or slats 32 disposed horizontally, one above the other. Each slat is inclined at a slight angle to the horizontal and positioned in fixed relationship to the other slats so as to constitute, in effect, a series of small louvers. These slats are maintained in proper fixed position with respect to each other by means of transverse vertical wires or stringers 34 which are disposed at appropriate intervals across the width of the screen. Pairs of these wires, one on each side of the slats .32, are twisted together as indicated at 36 to provide eyelets 37 through which the slats 32 extend. The construction of a screen of this type is well understood by those skilled in the art and is commercially available in several forms, one form being known as Koolshade.

The screen 12 is of greater dimensions than the glass sheets vertically so that it extends between the spacer elements 16 and 17 and protrudes beyond planes formed by the top and bottom, outer edges of the spacer elements 16 and 17 and glass sheets 13 and 14 for a distance of about Vs to /2 of an inch or greater. The screen should extend beyond the edges of the marginal edge spacer elements so that at least one slat 32 and usually two or more slats extend beyond the outer edges of the spacer elements and glass sheets. The horizontal dimension of the screen 12 may be substantially the same as that of the glass sheets or may be slightly'less than the horizontal distance between the inside surfaces of the spacer elements.

"The screen 12 is held tightly in place as described by means of a rigid, metal plate 40. The thickness of the plate may be about & to inch. The plate may be rectangular in shape. The plate 40 has slots or openings 42 extending in from one side thereof perpendicular to the side for a distance which maybe about to 4, preferably about /8, the width of the plate. These slots 42 are about inch in width or atleast of sutficient width to permit the stringer wires 34 to pass therethrough. The slots are spaced from each other along the length of the plate 40 according to the distance between the stringer wires '34 in the screen 12. The width of the plate 40 itself is the same as or slightly less than the combined thicknesses of the glass sheets 13 and 14, spacer elements 16 and 17 and mastic layers 28 therebetween. The width of the plate 40 is at least great enough so that the plate extends across the outer, exposed surfaces of the marginal edge spacer elements 16 and 17 and overlies a portion of the outer edges of the glass sheets 13 and 14.

The plate 40 is positioned in line with the edges of the glass sheets and marginal edge spacer elements by inserting the portions 44 of the plate which are between the slots 42 in between the first opening in the screen formed by the slats 32 and stringers 36 which extends beyond the plane of the edges of the glass sheets and spacer elements. The plate 40 is employed along the top and preferably along both the top and bottom edges of the unit as it is glazed. These are the edges which are parallel to the slats 32 of the screen. The screen 12 is pulled tightly so that it is suspended in a straight plane between the spacer elements 16 and 17 prior to insertion of the plate 40 through the screen.

When the plate 40 is inserted between the slats which extend beyond the edges of the unit, the screen 12 is held firmly in place. The portions of the screen which extend beyond the edges of the unit may be folded as at 46 so that they lie parallel to the plane of and adjacent to the plate 40. A strip of cushioning material 48 such as polyethylene may be inserted between the meeting faces of the plate and the edges of the sheets 13 and 14 so as to prevent chipping of the edges of the sheet.

In addition to being between the spacer elements and the glass sheets in their meeting areas, a mastic composition such as mastic composition 28 may also be provided along the outer edges of the unit overlapping the edges of the glass sheets, plate 40 and exposed slats of the screen 12 at 50 so as to provide a continuous i all of the weight of the screen moisture-proof seal around these assembled elements. Alternatively, or'in addition, a layer of mastic composition may be provided between the plate and the edges of the glass sheets and spacer elements.

A channel member 52 of U-shaped cross-section is afiixed around the periphery of the sealed unit. The channel member is made of metal such as stainless steel. The angle which the flanges or sides of the channel member form with the central portion of the channel member is slightly less than When the channel member is affixed to the edges of the sealed unit, these flanges are held apart to allow the sealed assembly to be inserted. After insertion of the assembly, the flanges are released and they spring back into contact with the faces of the glass sheets along a line thereon and exert a clamping force of about 5 to 20 pounds per linear inch on the sheets. This force causes the glass sheets to exert a pressure on the mastic composition 28 of about 15 to 50 pounds per square inch. The channel memher is thus held around the edges of the sealed unit under tension and the glass sheets, spacer elements, mastic and screen are held together. Other means may be employed to hold the glass sheets, spacer elements, mastic and screen in constant fixed relationship to each other.

In the assembling of the double glazed unit 10, the mastic layers 28 are first applied to the edges of the spacer elements 16 and 17 which face each other and which face the marginal edges of the glass sheets. The screen 12 is then placed between the spacer elements and stretched tightly between the spacer elements. The glass sheets 13 and 14 are then placed on the outsides of the spacer elements 16 and 17. The polyethylene strips 48 may then be placed along the top and bottom edges of the glass sheets 13 and 14 and the plate 40 is inserted between the protruding slats 32 of the screen 12. Thereafter, the mastic composition may be applied at 50 as a continuous strip around the edges of the assembled sheets 12 and 13, plate 40, screen 12 and spacer ele ments 16 and 17. In the final step, the channel member 52 is affixed around the edges of the assembly just described.

A further embodiment 60 of the invention is shown in Figs. 4, 5 and 6. In this embodiment the spacer element 17 is omitted and the light modifying screen 12 is held between the meeting faces of the marginal edges of the glass sheet 14 and the spacer element 16. The screen 12 is stretched tightly so that it lies against the inside face of the glass sheet 14. In all other respects, the structure and method of assembling the unit shown in Figs. 4, 5 and 6 are the same as those shown and described with respect to the unit shown in Figs. 1, 2 and 3.

The use of the plate 49 inserted between the portions of the screen 12 extending beyond the edges of the glass sheets provides a very simple and effective way of mounting the screen 12 within the air space 19 between the sheets. This construction maintains the screen 12 in a continuous, straight plane, parallel to the glass sheets and provides uniform reflection of sunlight and transmission of daylight. The plate 40 extending across the top of the multiple glazed unit performs a further function in that it bears the weight load of the screen and relieves the spacer element or elements from this burden. If the spacer element were required to bear a portion or 12, there would be a tendency for the spacer element to sag at the middle along the top of the unit. This tendency is overcome by the present construction.

Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details shall be regarded as limitations upon the scope of the invention except insofar as included in the accompanying claims:

I claim:

1. A multiple glazed unit comprising a plurality of sheets of glass separated at their marginal edges by at least one spacer element which is substantially flush with the edges of the glass sheets, a light modifying screen composed of horizontal slats held in spaced relation by vertical supporting means, said screen being mounted between the sheets of glass in contact with the marginal edge spacer element and extending. beyond the edges of the glass sheets and spacer element at the top and bottom of the unit, two plates positioned parallel to and overlying the edges of the glass sheets and spacer element along the top and bottom of the unit and passing through openings between tions of the screen so as to hold the screen rigidly between the glass sheets and means for holding the glass sheets, screen and spacer element in fixed relation to each other.

2. A multiple glazed unit comprising a plurality of sheets of glass separated at their marginal edges by a spacer element which is substantially flush with the edges of the glass sheets, a light modifying screen composed of horizontal slats held in spaced relation by vertical supporting means, said screen being mountedin touching relationship with and parallel to the inside surface of one of the sheets of glass and extending between the meeting faces and beyond the edges of the marginal edge spacer element and said sheet of glass at the top and bottom of the unit, two plates positioned parallel to and the slats in the extended poroverlying the edges of the glass sheets and spacer ele ment along the top and bottom of the unit and passing through openings between the slats in the extended portions of the screen so as to hold the screen rigidly within the unit and means for holding the glass sheets, screen and spacer element in fixed relationship to each other.

3. A multiple glazed unit comprising a plurality of sheets of glass separated at their marginal edges by a pair of spacer elements which are substantially flush with the edges of the sheets, a light modifying screen composed of horizontal slats held in spaced relation by vertical supporting means, said screen being mounted between the spacerelements and extending beyond the edges of the spacer elements at the top and bottom of the unit, two plates positioned parallel to and overlying the edges of the glass sheets and spacer elements along the top and bottom of the unit and passing through openings between the slats in the extended portions of the screen so as to hold the screen rigidly within the unit and means for holding the glass sheets, spacer elements and screen in fixed relation to each other.

References Cited in the file of this patent UNITED STATES PATENTS 

